Motorized trench roller



May 26, 1953 F. J. WRIGHT 2,639,652

MOTORIZED TRENCH ROLLER Filed April 21, 1948 5 Sheets-Sheet 1 JQVAK F. J. WRIGHT MOTORIZED TRENCH ROLLER May 26, 1953 5 Sheets-Sheet 2,

Filed April 21. 1948 T 3 R MW NJ. D a F May 26, 1953 F. J. WRIGHT 2,639,652

MOTORIZED TRENCH ROLLER Filed April 21. 1948 5 Sheets-Sheet 4 Ei y. 6'

//v vE/vTo/Q; FEED J.WFEIGHT,

May 26, 1953 F. J. WRIGHT MOTORIZED TRENCH ROLLER 5 Sheets-Sheet 5 Filed April 21, 1948 /NVEN7'O/2; FRED J WEIGHT,

ATT'Y.

Patented May 26, 1953 OFFlCE MOTORIZED TRENCH ROLLER Fred J. Wright, Columbus, Ohio, assignor to The Galion Iron Works & Manufacturing Company,

a corporation of Ohio Application April 21, 1948, Serial No. 22,390

6 Claims. (01. 94-50) My invention relates in general to road rolling machinery and more particularly to rolling machines known generally as trench rollers utilized in rolling material in a trench, formed, for example, alongside an existing road when the road is being widened.

It is one object of my invention to provide an improved roller of the above mentioned type.

It is another object of my invention to provide an improved roller having a wide rimmed roll and a bicycle unit including a pair of wheels and a power unit positioned laterally of the wide rimmed roll and connected thereto by a frame.

It is another object of my invention to provide an improved roller having a roll and. a bicycle unit including a pair of wheels that are preferably, but not necessarily, reversely steerable and in tandem relation wherein the roll and bicycle unit are connected by a main frame that includes linkage mechanism whereby the relative height of the planes in which the axes of the bicycle wheels and the axis of the roll may be shifted with respect to each otherj In carrying out the foregoing object it is another object of my invention to provide the main frame with a power means for adjusting the length thereof, which power means preferably, but not necessarily, forms a structural part or parts of the main frame.

It is another object of my invention to provide an improved roller having a roll and bicycle unit including a pair of wheels that are preferably, but not necessarily, reversely steerable that may be swung from substantially a tandem position or relation to substantially a parallel relation or position to permit towing of the roller as a twowheeled trailer when the wheels are swung to a parallel relation or position. i

In carrying out the foregoing object it is another object of my invention. to provide means for attaching the roller to a towing vehicle whereby the r011 of the roller may be supported above the ground to permit towing of the roller as a trailer.

It is another object of my invention to provide an improved roller wherein the main frame of the-roller carries a hydraulic pump and a motor for driving it and the motor which drives the roll of the roller is also carried by the main frame and is positioned substantially entirely within the lateral-dimensions of the roll and preferably, though not necessarily, drives the roll through a multiple lobe cam carried directly by the roll.

It i another object of my invention to provide an improved reversible roller having a. roll and laterally spaced therefrom a bicycle unit including a pair of reversely steerable wheels in tandem relation, the bicycle unit carrying a primary pump and motor for driving it and a hydraulic motor for driving the roll and wherein the frame connecting the bicycle unit and the roll preferably, but not necessarily, includes an operator's seat positioned above the roll.

Other objects of my invention will appear hereinafter the novel features and combinations being set forth in the appended claims.

In the accompanying drawings,

Fig. 1 is an end view in elevation with parts omitted of' a three-wheeled trench roller including features of my invention, the trench roller being shown in full lines in trench rolling position but connected to a tow-bar of a towing vehicle, the figure indicating in dot-dash lines the positions of the roll and bicycle wheels of the roller when the roller is being towed as a twowheeled trailer;

Fig. 2 is a side view in elevation with parts omitted of the trench roller shown in Fig. 1 showing the trench roller in trench rolling position;

Fig. 3 is a View in plan with parts omitted of the trench roller seen in Figs. 1 and 2 showing the bicycle wheels in parallel or towing position;

Fig. 4 is a view in section showing one side of the main frame of the trench roller, the View being taken on line 44 of Fig. 3;

Fig. 5 is a view in section of a fragment of the trench rolling roll of the roller, the section being taken substantially centrally through the roll;

Fig. 6 is a view in section, the section being taken substantially on line 6-45 of Fig. 5; and

Fig. '7 is a diagrammatic view of the hydraulic system of the trench roller.

Referring first to Figs. 1 through 4 of, the drawings, the trench roller shown therein embodying thefeatures of my invention is a threewheeled or tricycle type trench roller that includes a wide rimmed roll [9 adapted to roll material. such, for example, as stone or the like, into aditch formed alongside an existing road when the road is being widened. The wide rimmed roll Ill forms one of the wheels of the trench roller when the roller is operating to roll material into a ditch and this roll supports one side of themain frame H of the trench roller. The opposite side of the main frame H is supportedby a pair of reversible steerable pneumatic tired wheels 12 and I 3 which wheels are seen in Figs. 1 and 2 in bicycle or tandem position or relation and in which position or relax: tion their axes are parallel to the axis of the roll it. The bicycle wheels 42 and I3 are reversibly steerable and they may be swung as in dicated in Fig. 1 and as shown in Fig. 3 to a position or relation in which they are parallel to each other, that is, the position or relation wherein their axes are substantially coincident whereby the trench roller may be towed upon the wheels 1.2 and $53 as a two-wheeled trailer by a towing vehicle when the roll H! is supported from the ground by a tow-bar M of a towing vehicle IS, a portion of which is seen in Fig. 1

The main frame H of the trench roller .includes a pair of spaced upright side portions one of which forms the frame t6 of iflie bicycle unit that includes and is supported by the :pneumatic tired wheels 12 and I3 and the other side ll of which forms a support or irameimeansfor mounting the motor that drives the roll Ill and which is supported by the roll l0. That por-tion of the main frame il which forms the frame l6 oi the bicycle unit includes a :main beam i=8 having Welded to each of its ends on a vertical or steering axis an open ended tubular member :18; One of the tubular members 1-9 receives and amounts for rotation about the steering axis a wheel carrying ia-rm 2-6 for wheel l2 and the other tubular member L9 mounts a wheel carrying arm 2| for wheel IS in a simiiarrmanner. 'IEhe beam 18 of the bicycle unit (f6 supports apair of spaced vertical frame members 22 which members are connected at their bottom ends to a platform, bed .or base plate 23 adapted to support an internal combustion engine :24 which drives :a hydraulic pump unit 25. The platform,

bed or base plate .23 also supports-a tank 2i: #for hydraulic 'fiuid, which tank and pump unit :25 form parts of ahydraulic system hereinafter de scribed .in detail in connection with Fig. 7.

As :best seen in Fig. 1, the support or frame means ll of the main frame I l for the roll ldriving motor is placed laterally of that portion of the main frame H which dorms the frame 215 of the bicycle unit. As "best seen "in Fig. 4 ithe roll motor supporting or frame means f! of main frame 11 includes apa'ir of spaced vertically extending side members 27 connected at their bottoms -by :a cross bar 28 and approximately at their centers by a cross -member '29 formed of a pair of angle bars. Extending vertically between the cross bar members :28 and 29 and spaced inwardly :of the side members 21 is a pair of frame members 30. Each frame member 27 and the frame member 30 adjacent thereto is boned to'receive a pin '31 that is preferably locked therein to form a bearing for a frame strut,

members I! asby Welding their ends to thehorizontal frame members 28 31111.29.

The main frame H of the trench roller includes structure by which the horizontal plane in which the axes of the wheels 12 and 'I3 lie may be shifted vertically with respect ;to the 4 plane in which the axis of roll I!) lies, that is,

as seen in Fig. 1, the main frame I I includes connector members which connect the roll support or frame means I! and frame I6 of the bicycle unit whereby these members form upright sides of a parallelogram that may be moved vertically with respect to each other by a power means which is 'an integral part'of the main frame I I. The frame members connect the frame l6 of the bicycle unit and the frame means I! include an upper unit and a pair of spaced lower struts 38. The upper unit 35, as best seen in Fig. 3, includes tubular side members 8] each welded at one of their ends to a tube :33 the ends of which are received pivotally through removable bearing means by bearing blocks 39 welded directly to the main beam I 8 of the bicycle unit. The opposite ends of the tubular side members 31 are welded. to a tubular member 40 the ends of which are also received through "removable bearing means by openings formed ,in the uppermost ends of the lspacedside members 2-! of the motor supporting f-rameimeans H. aSui-table tubular bracing Struts 4! also connect the tubular sidemembers 1 with the tube 38 and these struts M are preferably weldedat theirlends to both -tubes;3-l and 3.8

The lower main frame struts 35 are each pivotally connected at oneend between a pair of spaced brackets 4-2 welded to the upright :f-mme members-22 of the bicycle unit 16 and the opposite ends of the struts 8,6 include cross heads 43 (see Fig. i) which are bearinged upon the pins 3.1 between the frame members .27 and 30.

tubular side members 31 of the upper unit 35 lea-ch have welded thereto adjacent the tubular member M a pair ,of downwardly extending brackets. ears or lugs (43' and reach of the struts lies directly below one tubular side member .3?! of the unit 1 .5 and adjacent its supporting bracket 4.2 has a pair of upwardly extending (brackets. ears or lugs M similar :to the brackets, ears or lugs 53' that receive in aligned opening: therein :a bearfurg or connector pin 45. Bearin or connector pin 45 extends through an end bearing portion of a piston rod 45 of a double acting hydraulic piston motor .or expandable and contraetahle main frame strut :4?! and. the cylinder 48 of hydraulic motor 1 1 includes an end. bearing portion received by a pin 49 extendins between and-through openings in the brackears for lugs 3" :of each side -member Ill.

as seen in Fig. 1, when the double acting hydraulic piston motor or frame strut 41 is contracted, that is, when its overall length is reduced, that portion of the main frame H which forms the motor supporting frame means -11 will be lowered as required'ior example, when the roll in is to operate to roll a ditch the bottom surface of which is below the road surface or that surface upon which the wheels 12 and H are riding and, of course, when hydraulic piston motor 4! is expanded, that is, when its overall length is increased the axis of the roll 10 will .be raised or elevated with respect to the axes of the wheels 12 and I3.

The mainframe II also includes a member .50 that extends upwardly from the center of the roll motor supporting frame l1 and as best seen in Fig. 1 this member '50 'is bent rearwardly to extend above the roll I0 and upwardly to form the back of an operatorfs seat that is positioned directly above the roll ID. The seat member 5. of the mainframe I I ,has secured thereto a seat cushion 5| and a seat'back cushion 52 and that portion of the member 50 that forms the back of the 'operators seat is braced from the seat portion thereof by a pair of tubular side bars or braces 53. The operators seat is positioned above the roll In so that an operator seated thereon may, by looking to either side, look directly into the ditch in which the roll ID is operating and the seat faces the, bicycle unit of the trench roller so that the operator may see the operating parts and the bicycle wheels of the trench roller by looking forwardly from his seat above the roll I upon the bicycle unit. Extending from the seat member 50 toward the bicycle unit, that is, toward that portion' of the main frame II that forms the main frame I6 of the bicycle unit, is an operators footrest or support 54 positioned centrally in front of the operator's seat and above the footrest 54 is a relatively narrow frame member or bracket 55 that supports a hydraulic control valve unit 56 by which the operator controls the operation of the trench roller. Bracket 55, as seen in Fig. 2, is T-shaped in order that the operator may straddle it with his legs and this frame member 55 is carried at its bottom by the seat member 50.

Referring again to that portion of the trench roller herein designated as the bicycle unit, the wheels I2 and I3 are reversely steerable and are interconnected by steering mechanism positioned above the main beam I8 of the bicycle unit I6. This steering mechanism includes a drag link 5! that carries at one of its ends a ball socket connector 58 and at its other end a ball socket connector 59. Ball socket connector 58 receives a ball of a lever or crank 60 that is keyed and secured directly to the upper end of the pivotal shaft or king pin portion of the wheel carrying arm 20 for swinging the wheel I2 about the steering axis of arm 20 and ball socket connector 59 receives a ball of one arm of a lever or crank 6| that is keyed or secured directly to the upper end of the pivotal shaft or king pin portion of the wheel carrying arm 2! for swinging the wheel I3 about the steering axis of arm 2|.

As viewed in Fig. 3 of the drawings the lever 01' crank 50 extends downwardly from the pivotal shaft or king pin of arm 20 and that arm of the lever or crank BI that is attached to the drag link 51 through ball socket connector 59 extends upwardly from the pivotal shaft or king pin of arm BI and thus if the wheel I3 and arm 6| are swung in a, counter-clockwise direction, as viewed in Fig. 3. the drag link 5I will rotate or swing the arm or lever 50, the wheel carrying arm 20, and the wheel I2, in .a clockwise or opposite direction, Thus, it will be seen that the wheels I2 and I3 are reversely steerable whereby the en'- tire trench roller may be steered around either an-inside or an outside curve with the axis of the roll Ill lying substantially on or coinciding with the radius of the curve. Steering motion or power is imparted to wheels I2 and [3 by a double acting hydraulic piston type motor 62 the piston rod 63 of which is pivotally connected to a second arm of the lever BI and one end 64 of the cylinder of the steering motor 82 is carried for pivotal movement upon a pin that is carried in a bifurcated bracket 65 on the main beam I8 of the bicycle frame IS. The wheels I2 and I 3 of the bicycle unit may be swung by the double acting steering motor 62 and the steering linkage simultaneously in different directions from their tandem positions, as seen in Figs. 1 and 2, for steering the trench roller while it is rolling a ditch and the wheels I2 and I3 maybe swung by the double acting steering motor 62 and the steering linkage to positions in which they are parallel, that is, to positions wherein their axes are substantially coincident, as seen in Fig. 3, whereby the trench roller may be towed by the towing vehicle as a two-wheeled trailer when the roll I0 is supported by a towing vehicle and elevated from the ground. This position of the wheels I2 and I3 is determined by fully contracting the steering motor 62.

Referring now to Figs. 5 and 6 and particularly to the structure of the roll I0 and the hydraulic motor which is contained within its confines and drives it, the roll I0 may be a casting and it includes a wide material rolling rim 66, a central disk or body portion 61 and a hub 68. Extending through a central bore in the hub 68 is a tubular axle 69 that is placed in the bore of the hub 68 by sliding it endwardly through the outer end thereof. Axle 69 is grooved circumferentially adjacent its outer end to receive a split locking member or ring Ill that seats or is confined, when axle 69 is in place, in an enlarged portion of the central bore of the hub 68. Ring Ill prevents roll ID from slipping off of the axle 69. Axle 63 is locked by a key II to the roll In in order that it will rotate therewith so that the axle 69 will function as a valve or port shaft for the cylinders of the radial type hydraulic motor that is indicated generally at I2 which drives the roll I!) in reverse directions. Axle 69 also extends centrally through a tubular motor cylinder block I3 that includes a plurality of hydraulic motor cylinders I4 in a radial flange portion 86 thereof. The tubular cylinder block I3 includes at its end remote from the hub 68 of roll ID a bore or cup I5 that receives a tapered roller bearing I6 that surrounds the axle 69. Bearing I6 is held in position by a grease retainer and bearing adjusting collar 11 that is sawed or split to provide a locking portion I8. Collar 11 is threaded on the axle 69 for securing the axle within the cylinder block I3 and for adjusting the bearing I5 and a motor block supporting bearing 8|. There extends through the locking portion I8 of collar 17 an adjusting screw I9 that abuts the body of collar 11 and when adjusting screw I9 is tightened the locking portion I3 is sprung sidewardly to lock collar II upon the threads of axle 59. The end of the cylinder block I3 adjacent the hub 58 is flanged at 8!) to receive the tapered roller bearing 8| received in a bearing cup formed directly in the hub 68 of roll Ill. The tubular cylinder block I3 is keyed into the supporting unit or housing 33 that is received and carried by the side ll of the main frame II of the trench roller by a key 82 and it is held therein against axial movement in one direction by a collar 83 threaded thereon that abuts one end of the housing 33. Collar 83 is locked to housing 33 by a set screw 84. The housing 33 is held against axial movement in the other direction by a shoulder 85 formed on the cylinder block I3.

From the description of the roll I0 and its associated mechanism thus far given it will be obvious that the side H of the main frame II that is supported by the roll I0 is carried by the support or housing 33 that is fixed therein which in turn is carried by the cylindrical motor block I3 that is fixed therein against rotation and axial movement and that one end of motor block I3 is carried directly by the hub 68 of roll I0 through the roller bearing BI while the other end of motor block I3 is carried through the roller bearing it by the axle 69. Motor block I3 includes a flat disk or flange portion 86 positioned adjacent the central disk or body portion 61 of the roll I that includes radially extending cylinders of the reversible hydraulic motor I2 that drives the roll Id.

As seen in Fig. 6 there are twelve of the cylinders I4 and each of these cylinders M includes a piston guiding bore 06 and a larger bore portion, chamber or cylinder head 81 positioned radially inwardly oi the piston guiding bore 86. Each cylinder head 0'! is connected with the bore or surface of the cylinder block '5. that surrounds the axle 69 by a single bore or port 38 for the admission and exhaust of hydraulic fluid to and from the cylinder head 0?. A piston 89 reciprocates ineach of the bores 86 and the outer end of each of these pistons 55 is cross bored to receive a cross pin or head it that reciprocates in slots formed in the opposite sides of the pistonguiding bore 88. Upon each end of each cross pin head there is carried an antifriction bearing or roller GI the outer races of which engage and. ride upon identically spaced cam surfaces 9-2 having a plurality of lobed cam surfaces 93 that are formed integrally with a casting 04 secured directly to the central disk or body portion fi'l of the roll It by cap screws 9-5.

The outer surface of casting 00 forms a brake drum 96 that is adapted to be acted upon by the brake band 91 (Figs. and '7) of a hydraulic brake mechanism of the trench roller. The reversible hydraulic motor IE is contained entirely within the confines of the roll 0- and a part of the central disk or body portion of the the roll I0 forms one side wall of a housing which encloses the motor 12. The outer wall of this enclosing housing is formed by the wall of the casting 94 that includes the multiple lobed cams 32 and the other side wall of the housing is formed by a wall or flange 98 that surrounds the end of the housing 33 adjacent the shoulder .85 of the cylinder block I3.

As seen in Fig. each of the multiple lobed cams includes seven lobes 03 and there are twelve pistons so acting through anti-friction cam rollers 5H upon these seven lobes to produce or cause rotation of the multiple lobed cams 92. It will be seen that each lobe 05'; of each cam '93 is symmetrical, that is, its cam surfaces lying to each side of its apex are identical in contour and therefore each lobe 92 provides a rising and falling cam surface to a cam roller SI rolling thereover. Because there are a greater number of pistons P89 acting upon a lesser number of ca m surfaces, the radial piston motor it has no dead center or inoperative positions since some of the cam rollers 9| of some of the pistons 83 are at all times in engagement with both the rising and falling surfaces of the lobes 93 of earns 92. The direction of rotation of the cams and consequently the roll I 0 about the stationary motor block I3 will be determined by the supply of hydraulic fluid to certain of the cylinders 74, as is now to be described.

The housing 33 is provided with two bores 90 connected with conduits I00 and I0! of the hydraulic system or apparatus of the trench roller. One of the conduits 99 opens at its inner end into a conduit I02 in cylinder block 73 that leads or opens through the central or axle receivingbore of the motor block 13 at one side of the flange portion thereof that: includes the mob! cylinders I4 andthe other. conduit 99 opensnt its inner end into a conduit I03 in the cylinder block 73that leads and opens through the central or axle receiving bore of the motor block 73 on theopposite side of the flanged portion thereof that includes the motor cylinders I4.

The tubular axle 58 is: provided with spaced circumferential grooves or channels I04 and Ill in communication with conduits I02 and I03, respectively. From the circumferential groove or channel I04 there extends in the axle toward the opposite channel I05 seven notches, ports or stub channels I06 and there extends from the channel I05 towardithe channel I00 but centrally between the stub channels I 00 seven notches, ports or stub channels I01. -.As seen in Fig. 5, the stubchannels I06 and I 07 extend from their respective circumferential channels I04 and I05 only such distance as, to lie under andcommunicate with the ports leading to the cylinder heads 07 of the cylinders M as the axle 50 rotates in the cylinder block Conduits I 00 and IOI are adapted to act as supply and exhaust conduits, respectively. for hydraulic fluid flowing to and from the motor 12 and their order may be reversed to reverse the direction of rotation of the roll I0, that is, conduit I 0I may bev caused to become the supply conduit and conduit I00 may bevcaused to become the exhaust conduit, as is more fully described hereinafter in connection with Fig. 7. I

As seen in Figs. 5 and ,6, when conduit I00 is the supply conduithydraulic fluid under pressure will pass through conduit I00, conduits 99, I 02, the circumferential groove I04 in axle 69 and into the stub channels I06 and through those ports 0.0 of cylinders 14 that are in communicat tion with stub channels I06 into the cylinders to force their pistons 89 outwardly which, of course, will cause rotation of the cam 92. and the roll VII] in one direction.

As seen Fig. 6 when the stub channels I06 are supplied with hydraulic fluid under pressure the motor cylinders that are in communication with them through the ports 88 are all on the counter-clockwise sides of cams or lobes 93 and outward movement of their pistons will cause rotation of the cams 92 in a clockwise direction. The cylinders whose pistons and cam rollers SI are engaging the clockwise side of the cam surface of the cam lobes 93 have their ports 88 in communication with the stub channels I01 and hydraulic fiuiddisplaced from the cylinders 14 by inward movement of their pistons 80 will be conducted .to the conduit I.0I acting as the exhaust conduit inthe hydraulic system through channel I05, conduit I 03 and the other conduit 99 in housing 3,3. When the stub channels I 01 are caused to be the supply channels for hydraulic fluid under pressure then the stub channels I00 will conduct the fluid exhausted from the cylinders I4 and the direction of rotation of the cams 9! and roll I0 will be reversed.

Offset from its hub 68, roll I0 carries a ball I08 of a trailer hitch that is adapted to be re- .ceived in a socket mechanism I09 (Fig. 1) attached to the rear end of the tow-bar H on the truck or towing vehicle I5, and when connected thereto the roll 10 may be rotated by the hydraulic roll driving motor "I2 which, .of course, will lift the roll I0 from the ground to the position indicated in dot-dash lines in Fig. .1 in which position the roll will be locked by the brake band .9]. It is, of course, to be understood that the wheels I2 and I3 will be swung to and held in their parallel position indicated in Fig. 1 and shown in Fig. 3 by the steering motor 62 when the trench roller is to be towed by the truck or vehicle I5 as a two-wheeled pneumatic tired trailer.

Referring now to Fig. 7 of the drawings wherein the hydraulic system of the trench roller is diagrammatically shown, the hydraulic system includes a closed high pressure and high volume hydraulic circuit which includes a high pressure, variable delivery, reversible pump IIO which is capable of being adjusted from a zero output volume to a large or high output volume of hydraulic fluid under high pressure. Pump H is contained in the pump unit 25. The high pressure and high volume hydraulic circuit also includes the high pressure and high volume, reversible radial type hydraulic motor I2 that reversibly drives the roll I0 directly through the cams 92, and the conduits I00 and I M that connect the high pressure, variable delivery, reversible pump IIO with the motor I2. The pump IIEI, as seen in Fig. '7, is discharging or pumping hydraulic fluid into the conduit I00 to drive the roll motor I2, as previously described in connection with Figs. and 6, and the conduit IOI conducts the hydraulic fluid exhausted from the motor I2 to the port of the pump IIO acting as the intake or suction port thereof. Hydraulic fluid in the closed circuit including pump IIO, conduit I00, motor I2 and conduit IOI is re-circulated, that is, fluid exhausted by the motor I2 flows back to the pump IIO through the conduit IIlI and is pumped by the pump III] through'conduit I00 back to the motor I2. The output volume of pump IIO, as previously set forth, may be varied from zero to a high volume and the pump I I0, as shown diagrammatically, includes a rotor III having reciprocating vanes II2 that operate in a ring or housing II3 the axis of which may be shifted with respect to the axis of the rotor III. It will be seen, of course, that when the axis of the rotor II I and the axis of the ring or housing I I3 coincide, that the pump III) will not be oper-' ating to produce any output of hydraulic fluid either into the conduit I00 or H. In order to cause the pump I ID to pump hydraulic fluid, the axis of ring or housing I I3 may be shifted or offset with respect to the axis of the rotor I I I either to the right or left'and the amount of offsetting of these axes determines the output volume of the pump IIO. If the ring or housing H3 is shifted to the left, as seen in Fig. 7, the pump I I0 will discharge into conduit I00 and if the ring or housing H3 is shifted to the right, the pump I III will discharge into conduit NH. The ring or housing H3 is shifted to the right by a piston motor I I4 and to the left by a piston motor I I5.

The entire hydraulic system also includes the tank 26 which is a reservoir for hydraulic fluid used in the hydraulic system. From the hydraulic tank 26 a supply conduit II6 leadsfto a low volume, low pressure, constant delivery pump III. Pumps H0 and II! are both contained within the pump unit 25 and may both be driven from the same shaft, which shaft is driven by the internal combustion engine 24. The hydraulic fluid pumped by pump I I! is conducted through a conduit II8 into one end of the control valve unit 56. For the moment it will suffice to say of the control valve unit 56that hydraulic fluid normally passes through it and is discharged from the opposite end thereof into a conduit IIBthat leads to conduits I20 and I'ZI 10 which connect, respectively, with conduits IOI and I00.

Conduit I2I includes a check valve I22 and conduit I includes a check valve I23. When the closed hydraulic circuit including pump IIO, motor I2 and conduits I00 and IOI is operating as previously described, the output of hydraulic fluid pumped by pump III] is supplied to motor I2 through conduit I00 and the pressure in conduit I00 will close the check valve I22 in conduit I2I. Conduit IIlI, which is acting as the low pressure conduit of the closed system and through which hydraulic fluid is being conducted from the motor I2 to the intake or suction port of motor IIO, will be subjected to a relatively low hydraulic pressure and check valve I23 in conduit I20 will open under pressure of the hydraulic fluid pumped by pump II! in conduits H9 and I20 to admit the hydraulic fluid pumped by pump 'I I! to the conduit I0 I. It will be seen, of course, that the volume of hydraulic fluid flowing into conduit IOI will be considerably less than the volume of the hydraulic fluid discharged from the motor I2 when the pump H0 is operating at full capacity but it will also be seen that an amount of hydraulic fluid substantially equal to the amount added by the pump I I! to the conduit IOI must be displaced from the low pressure conduit IOI. It will be seen also that when the output volume or pressure of pump H0 is directed into conduit IOI, the pressure in conduit IOI will close check valve I23 and check valve I22 in conduit I2I will open to pass the hydraulic fluid pumped by pump II'I into the conduit I00 acting as the low pressure or suction side of the high pressure closed system. In order to permit hydraulic fluid to be displaced from the conduits IOI and I00 there is connected to the conduits I00 and IOI of the high pressure, high volume closed circuit, a shiftable spool type valve I24.

Valve I 24 includes a body I25 having a central bore I26 in which there is slidably received a piston or spool I21. The ends of body I25 are closed by caps I28. The body I25 of valve I24 includes a threaded opening I29 that receives a conduit I30 connected to the conduit I00 and the body I25 includes another threaded'opening I3I that receives a conduit I32 connected to conduit IOI. Threaded opening I29 connects with an annular channel I33 formed in the bore I26 and the threaded opening I3I connects with another annular channel I34 in the bore I26. Spaced outwardly of channel I33 in an annular channel I35 that connects with a threaded exhaust opening I36 in the body I25 and spaced outwardly of the annular channel I34 is an annular channel I31 that is also connected with the threaded exhaust opening I36. Threaded exhaust opening I36 receives a conduit I44 in which there is interposed a pressure relief valve I38. Valve I24 is a conventional valve well known to those skilled in the art and in actual construction this valve includes an annular groove positioned centrally of the bore I26 that is connected with a threaded opening in the side of the body I25. This central annular groove is unnecessary to the present invention and therefore the port communicating with it is closed by a pipe plug.

The piston I21 of valve I24 includes three spaced lands I39, I and MI. Lands I39 and I40 are connected by a reduced diameter portion I42 of the piston I2! and lands I40 and MI are connected by a reduced diameter portion I43 of the piston I21. The lands are so spaced 1 i that when the piston I21 is moved downwardly. as shown in Fig. '7, the annular channel I34 connected with opening BI is connected through the bore I26 with the circular opening I31 which in turn is connected to the conduit I44 which leads through the pressure relief valve I38 and to the tank or reservoir 26. The spacing of lands I39 and I40 on piston I21 is also such that when the piston I2! is positioned as seen in Fig. '7 to place the annular channels I34 and I3"! in comniunication, that communication between the annular channels I33 and I35 is blocked by land I39. When the piston I2! is shifted upwardly to its top position, the channel I34 will be isolated by the land I4I from the channel I31 to block the flow of fluid through the conduit I32, and this occurs when conduit I III is acting in the high pressure side of the closed hydraulic circuit.

The piston or spool I21 is shifted from either of its positions described to the other by the differential of hydraulic pressures in the conduits I and IOI. A control conduit I45 connects conduit I38 and consequently conduit I3!) with a chamber 46 in valve 254 formedby the cylindef head I 28, the bore I26 and the head of piston I27 adjacent land I39 and a conduit I 47 connects conduit I32 and consequently conduit ill! with achamber I48 in valve I 24 similar to chamber I46 but at the opposite and er piston I21. It will be seen that if conduit IIlI is placed, by reversing the output of pump I II), in the high pressure side of the closed circuit, conduit I 4! will admit fluid under pressure into chamber I48 to force the piston I21 upwardly which, of course, will cause the land I4I to block the channel I3? to stop the flow of hydraulic fluid from the conduit I 32 to the exhaust conduit I44 and that the fluid in chamber I46 will be displaced through conduit I45 into conduit I which will be connected by the shifting of the piston I21 through channel I33, bore I26, and channel I35 to the conduit I44. Thus either conduit I00 or IOI when placed in the high pressure side of the closedcircuitwill be stopped or dissed off from the conduit I44 by the valve I24 and the conduit "ill or IOI which is acting as the low pressure side hi the closed circuit will be opened by the valve I24 to conduit I44 which is" connected to the tank 26 through the pressure relief valve I38.

As previously described, when the conduit IIII is in the low pressure side or the closed circuit a volume of hydraulic fluid substantially equal to the volume of hydraulic fluid placed therein by pump II'I must be displaced therefrom and since conduit IUI is connected to valve I24; conduit I44 and pressure relief valve I38 to tank 26, hydraulic fluid may be displaced from the conduit IOI by opening the pressure relief valve I $6.

The hydraulic fluid supplied to the closed hydi'aulic circuit of motor 12 and pump H0 by pump II! will be at a lower temperature than the hydraulic fluid exhausted from the motor 12 and thus it will act as a cooling medium or fluid tor the high pressure closed circuit. It will also act as make-up fluid, that is, it will replace inthe high pressure closed circuit any hydraulic fluid lost therefrom through the glands, joints and the like of pump III) and motor I2.

It is important to note that the hydraulic fluid pumped by pump III into the high pressure closed hydraulic circuit entersthe circuit between that port of the motor 12 that is acting perature of the hydraulic fluid passing frontthe 1 Throughout all exhaust port of the motor T2. speeds at which the motor 12 is operating the cooling and make-up hydraulic fluid pumped by pump II! will cause hot hydraulic fluid to be displaced from the low pressure side of the high pressure closed circuit through the pressure relief valve I 38.

It will be seen, of course, that if motor 12 is being driven at such speed or is adjusted so that the intake volume of pump III) is less than the output volume of pump III, the entire supply of hydraulic fluid for pump III] will be comprised of the hydraulic fluid pumped by pump H1 and the volume of hydraulic fluid pumped by pump II1 which is in excess of the intake volume required by pump IIO will be discharged through valve I24, conduit I44 and pressure relief valve I38 to the tank 26. Pressure relief valve I38 is adjusted to open at a relatively low pressure and it functions to insure that at all times the conduits comprising the low pressure side of the high pressure closed circuit are maintained filled with hydraulic fluid.

The hydraulic circuit of the trench roller includes a low pressure circuit of which tank 26, conduit II6, pump 1, conduit II8, the hydraulic control valveunit 56 and conduit II9 form a part. In addition to the function of the low pressure circuit of supplying cooling and make up fluid to the closed high pressure circuit, the low pressure circuit functions as a control circuit to operate the motor or frame struts 41, the steering motor 62, a double acting brake cylinder motor I49 associated with the brake band '91 and the piston motors H4 and H5 of the high pressure variable delivery pump IIO. All of the motor units in the low pressure circuit are con trolled by individual valves of the control valve unit 56. The control valve unit 56 is fully described and claimed in my 'co-pending application, Serial No. 627,848, filed November 10, 1945, now Patent No. 2,486,087, dated October 25, 1949, for a Hydraulic Valveand' therefore is described only briefly here. As previously set forth, hydraulic fluid pumped by the pump III normally flows through control valve unit 56 and is discharged therefrom into conduit II9. The control valveunit 56 is comprised of a plurality of identical individual banked valves of tile Spool or shiftable core type and one of the valves of the control valve unit 56 is indicated at I50. Valve I50 controls both of the piston motors m and H5 of pump H0. The construction of valve, I50 is such that when its control lever I5I is moved to one position, hydraulic oil flowing therethrough iro'm conduit H8 is diverted into a conduit I52 that leads to the cylinder head of motor H5 and this hydraulic fluid operates the piston motor H5 to move or shift the ring or housing H3 to the right, as seen in Fig. '7. Movement of the ring or housing II: to the right causes the piston of piston motor H4 to displace hydraulic fluid from the cylinder thereof through a conduit I53, which fluid enters the body of the valve I50 and is caused to flow through the other valves of the unit and into the conduit IIO. When the control lever I5I of valve I50 is moved in the opposite direction, the flow of hydraulic fluid is reversed from that described in the conduits I52 and I53 to shift the ring or housing I I3 to the left and when the control lever I5I of valve I50 is in a central or neutral position, the conduits I52 and I53 are blocked whereby the piston motors II4 and H5 will be locked to maintain the ring or housing H3 in adjusted position. It is the shifting and positioning of the ring or housing II3 with respect to the rotor III which affects the output volume of hydraulic fluid being pumped by pump IIO which, of course, controls the speed of operation of motor I2 as well as its direction of operation fordriving the roll I of the trench roller. The control valve unit 56 includes three other valves, I54, I55 and I56, all identical in construction with valve I50. Valve I54 controls the operation of the expandable and contractable frame struts or double acting hydraulic piston motors 41, which struts or piston motors are connected in parallel and to the valve I54 by conduits I51 and I58. Valve I55 controls the operation of the steering motor 62 through conduits I59 and IE0. The valve I56 controls the double acting piston motor I49 associated with the brake band 91 for positively contracting it about the drum 96 and for positively expanding it therefrom. The valve unit 55 includes a drain conduit for collecting hydraulic fluid that might support its cores or spools and this drain conduit is connected by a conduit I62 that returns the hydraulic fluid to the tank 25.

From the description of the valve unit 55 herein given it will be seen that when hydraulic fluid is diverted, for example, from conduit IIB by the valve I50 into conduit I52, a volume of hydraulic fluid substantially equal to the volume of fluid diverted into conduit I52 will be supplied through conduit I53 from the piston motor I It to the conduit I9 and thus the flow of hydraulic fluid through conduit H0 will be uninterrupted. Because all of the valves I50, I54, I55 and I56 are alike, when any one of them is actuated to divert hydraulic fluid to one of the control motors of the trench roller, then a volume of fiuid substantially equal to that diverted by the valve to the motor which it controls will also be displaced from the motor through the valve and into the conduit I i9. The structure of the valves is such that any two or all of them may be operated to control simultaneously their respective motors.

All of the motors controlled by the individual valves of valve unit 55 are expandable and contractable piston and cylinder type motors and by referring to the motors or expandable and contractable frame struts 41 for an example it will be seen that should the control lever of valve I54 be moved to cause the hydraulic fluid pumped by the pump II? to be diverted to the conduit I58, the pistons of the struts of motors 41, as seen in Fig. 7, will move upwardly to the upper limit of their strokes and when the pistons reach. this upper limit they will have displaced substantially all of the hydraulic fluid thereabove from the cylinders 48 through the conduit I51 into the conduit H5. It will be seen that when the pistons of the motors 41 reach this upper limit of their strokes and can travel no further, the conduit I55 will be eiiectively blocked and therefore the pump II! would stall, thus stalling the pump IIO because both pumps III and H0 are driven from the same shaft. Accordingly, I have provided a by-pass circuit including a pressure relief valve I6i that connects the conduits H8 and IE9 to by-pass the control valve unit 56. The by-pass including pressure relief valve I6I will operate when any one of the piston motors controlled by any one of the individual valves of the control valve unit 56 is stalled or has reached the end of its stroke and therefore there will always be hydraulic fluid flowing in the conduit H9. It will also be seen that while the motors controlled by the valves of control valve unit 56, as herein shown, are all of the double acting piston and cylinder type, if desired, one or all of the motors may be of the rotary type.

In the operation of my improved three-wheeled or tricycle type trench roller, the roller will be attached to the tow-bar I4 of the towing vehicle I5 and with its wheels I2 and I3 swung to their parallel positions indicated in Fig. 1 and locked in that position by the steering motor 62 and with the roll I0 in, the elevated position indicated in dot-dash lines in Fig. 1 and locked in that position by the brake band 91, the trench roller may be towed along a road or highway as a twowheeled trailer to where it is to operate to roll material into a trench formed along the side of the road when the road is being widened, for example. In order to disconnect the trench roller from the towingvehicle the brake band 91 is released and the roll I0 is permitted to rotate upon the ball I00 connected to the hitch mechanism I69 of the tow-bar I4. After the roll I0 has swung eccentrically about the ball I68 and has engaged the ground, the hitch mechanism I09 holding the ball I08 will be released therefrom. With the engine 24 running, the operator will then operate the control lever of valve I55 to swing the wheels I2 and I3 to their tandem or steering position and he will then operate the control lever I5I of valve I50 in the direction required to operate the motor I2 to cause the roll I0 to propel or drive the trench roller to the ditch that is to be rolled. During this time, of course, he will operate the control lever of valve I55 to steer the trench roller as required by swinging the wheels I2 and I3 together in opposite directions. The wheels I2 and I3 are revereibly steerable, that is, swingable in opposite directions about their axes simultaneously in order that the trench roller may roll in a curved ditch, that is, so that the roll I0 may travel along either an inside or an outside arc the radius of which lies substantially upon the axis of the roll I0. It will, of course, be seen that if the trench to be rolled is not completely filled with the material to be rolled therein that the level of the material in the trecnh and upon which the roll I 0 is riding will be lower than the surface of the road upon which the bicycle wheels I2 and I3 are riding. In order that the rolling surface of the wide rim of the 'roll I0 may be maintained horizontal, or if desired at an angle, while rolling the shoulder of the road, the operator by operating control valve I54 of the control valve unit 56 may cause the expandable and contractable main frame struts 41 to operate the frame means which connects the roll I0 with the bicycle unit to swing as a parallelogram whereby the support or frame member IT for the roll motor 12 and the frame of the bicycle unit I6 will move vertically with respect to each other to shift the plane in which the axes of the wheels I2 and I3 lie with respect to the plane in which the axis of the roll I0 lies and as the operator operates the roll in reverse directions along the trench, rolling;

15 additional material themeihto thereby raising: the lievelz of the: material thereihg. he: may intermittently operate the fllalllfi stcut membens 41: to raise plane in which the axis of the roll I'll thereby maintaining: the: surface of the. material which he rolling into theditcha level. The. frame.- strut motors 43 may also-he operated to. hath the wheels 2 and; I3 and the fell ill: tel-lean laterally togetheirtoeither side otthe vertical wherebysloping shoulders; and the like may blidOiIfid by'tlna? roll: lit.

When the txench roller is to be mmredor tramspmzted for: example. to another trenchilocated a distance away, the trench; roller will be connected to the tow-hair H of the towing vehicle: l5 by placing. the ball N8 in; the: hitch; by operating; the control. valve: I550 to cause the motoa; E2: to rotate the. roll i0? about the axis of the ball; I108; which is oifset. with respect/co the axis ot the roll: to thereby swinging the izcil-eccentrically to the pcsitiorl-- shown; in dot-daslolines in Fig. 1; and. opezrazton" will operate value IlEGI to set the; brake. oi the roll IO the brake: band 91- upon the drum athen operate the valve. t55 to. swing the wheels 13 and Hi to theiit parallel or twowheeled trailer position and whom valve r55 ismeturnedto its neutral positicozx,v the wheels [2 and, I3 will be looked the parallel on twowheeled trailer positiom.

From th foregoing description of! the trench pollen and. its; operation it will be: apparent: that I- have pirovided an improved three-wheeled roller including a; bicycle unit; having a pain of iteversely' steetab'le: wheels at oneside thereof that may be swung. fizom tandem position. to parallel position and; includes as the third wheel of the roller awidezri'mmecl roll carried by an ad'- jostable foam-e means that spaces. it to one side 0f the bicycle wheels and; by which the plane in which. the: axesof the: bicycle unitzwheelsl-i'eand the plane inwhich the: axis of the wide: rimmed roll l lies: may? be shifted. VElitiCEtlIYWith respect to each other and: by which these? planes, or: axes, may be? shitted: from horizontal positions.

It will also: be seen that I. have provided a; tnench. nolleix wherein the; hydraulic apparatus and the improved systemlthereoaffis carried by the main-t frame.- ofthe trench roller: or: more specifically by the: mainfoame: of the: bicycle: unit there 0t, and: wherein the motor that the: roller is contained entirely within the confinesof the WidQ'lliiTl: of the: roll drives the toll: directly througha multiplelobed cam It will also be seen that the: hydraixliccircuit of the trench roller-is: an improved; circuit wherein at a-lltimcs pat-t on all: of the hydraulic fluid dischangedfroma secondary orlow'pitessure ci rcuit,l which. pneferablyis an contno'lcircuit, including a. constant volume pump;v is led to the intake port of. a high pressure" and preferably a variable: volume pump ina main; primary, or high pressure substantially closed; circuit from which hydraulic fi'uid. is constantly being displaced-as it passes; or is exhausted: by a high pressure reversible motor therein because of the addition-of the cooling and make-upfluid thereto dischangedl item the secondary circuit. This bydraulic. circuit is; described and claimedin my divisional' application, Serial No. 154,790", filed April 83, 1950;, now Patent No: 2,621,479, dated December 1162; 1952,. for? a Hydraulic System Iii' eluding a: Cooling Gircuitifor the Pump Thereof.

(obviously those skilled in the artmay make yaulious changes 1111 the details and 'a'nrangement 16 oil without. departing: firom: the spirit and scope. at the invention as. defined by the hereto appended-1 and lwishtherefore not to be restricted to the.- precise construction hereiu disclosed.

thus desccilted and shown an embodiment of my invention, whatil desire to secure by LetterslPatent of the; United States is:

'1', A roller" including: a; wide rimmed roll, a bicycle uni-t positioned laterally of said null clucli'ngra mime, tandemlsteenahle wheels on: said ftameanxi; a power unit, 'and'fram means pivotal-1y interconnecting: said roll and said unit, fname: means including sp'acedl parallel motion. linkages pivotally connected at their ends ahdmeansifon pivotally adjmstingv said; linkages to adjiust the relative heights of said roll and saidl bicycle; unit.

2, A reversible. three wheel: col-lei: including. a roller a, largeri-mmed heavy roll rotatably mounted relative to saidfrazme, alctera-ll'y spaced bicycle unitincluding: 9:. frame and. a. pair at tandem steerable-wheels, a. primary driving motor and a pumpdmivenxthereby carried by said bi cycle unit frame .a hydraulic driving motor earned by said roll, and a. third frame. intercom netting roller frame and said: bicycle unit frame; said: third fine-me: including parallel: mutton pivoted to sarld roller: frame and said bicycle: mitt frame, andsadjusting means to adjust parallel motion mechanism and conseqently the relative heights of: said roll and: said bicycle 3. A. roller inclnd m -a roller frame, a, wide rimmed; 1101-], cotafia'bl'y connected: to roll relative to said frame, a. bicycle unit positioned laterally of. roll including a frame and. a pair of tandem. steerable wheels and a power unit, a third frame means ihtercomiecting said roller frame and saioii bicycle: unit frame, said third frame means including spaced parallel motion linkages pivoted to said roller frame and said bicycle unit frame and means for pivotally adjusting said linkages to adjust the. relative heightsof said roll and said bicycle unit, and means for adjusting said: wheels i-"eversely and operable to adjust them from substantially tandem to substantially parallel positions;

a. A roller including a roller frame, a wide rimmed roll rotatably connected to roll. relative to said frame, a bicycle unit positioned laterally of said roll including a flame and a pair of tendem steerable: wheelsiand a power unit, a third frame: means, hiterccmiecting said roller frame and said bicycle unit frame, said third frame means incluiding'spaced parallel motion linkages pivoted to-said roller frame and said bicycle unit frame. and means for pivotally adjustin said li'nkagesto adjust the relativeheights of said roll and said bicycle unit, means for adjusting said wheelsreversely and operable to adjust them from substantially tandem to substantially parallel positions, and eccentrically mounted means associated with said roll for attaching said roll to a; truck and lifting it off the ground by rotating said roll. 1

5'. A roller including a roller frame, a wide rimmed roll rotatably connected to roll relative to said frame, a bicycle unit positioned laterally of said roll including a frame and a pair of tande'm steerable Wheels and a power unit, a third framemeans interconnecting said roller frame and said bicycle unit frame, said third frame means including spaced parallel motion linkages pivoted t'o-sai'd roller frame and said bicycle unit frame and means for pivotally adjusting said linkages to adjust the relative heights of said roll and said bicycle unit, means for adjusting said Wheels reversely and operable to adjust them from substantially tandem to substantially parallel positions, and means for attaching said, roll to a truck and lifting it off the ground by rotating said roll, said lifting means including an attaching member carried by said roll and mounted eocentrically 0f the axis of rotation thereof.

6. A roller including a frame, a heavy roll carried, thereby, steering wheels connected to said frame, means for holding said steering wheels in looked parallel relation, a motor for driving said roll, and means for attaching said roll to a truck and for lifting it on the ground by rotating said r011 including a ball carried by said roll and mounted eccentrically of the axis of rotation thereof.

FRED J. WRIGHT.

References Cited in the file of this patent UNITED STATES PATENTS Number 

